Flex fuel issue

[Surfdog SS]

I just got my car back from doing a cam kit, zl1 fuel pump, flex fuel, 1000cc injectors. I'm running 8lbs of boost. When they did the flex fuel tune running e50 it didn't gain anything, they said they never seen that before. Added timing and got nothing but cleaned away the slight knock it saw. Any ideas on this? Pretty much left it I need to add an aux pump next and go full e85 with the restrictor plate out roughly 12lbs. But they said they alway see around 50hp gain on going with e50 weird right.

[FasNuf]

wouldn't be the first time I saw it, but did they enable the sensor?

[ZL1_Chris]

[eLeSthree]

Did they show you the tune was actually adding the Flex fuel timing during the pulls?

Are they using lambda to tune? What was the EQ ratio during the pull?

[Surfdog SS]

Originally Posted by FasNuf

wouldn't be the first time I saw it, but did they enable the sensor?

Yes they enabled the sensor, he shouldn't be able to read the e content if he didn't right. he said he blended 2 degrees but same numbers and today when I talked to him he said only one other time he seen that with a ctsv he worked on.

[Surfdog SS]

Originally Posted by eLeSthree

Did they show you the tune was actually adding the Flex fuel timing during the pulls?

Are they using lambda to tune? What was the EQ ratio during the pull?

I don't know what they were doing, but they aren't new to this. Was just curious if anyone has ever heard of this.

[eLeSthree]

Originally Posted by Surfdog SS

Yes they enabled the sensor, he shouldn't be able to read the e content if he didn't right. he said he blended 2 degrees but same numbers and today when I talked to him he said only one other time he seen that with a ctsv he worked on.

If I understand you right, he added 2 degrees of timing for E50?

Typically you would add 7-8 degrees to the Flex Fuel table, on a sliding scale based on ethanol content. So if you had 50% ethanol you should have been adding %62.5 of that 8 degrees. So if setup correctly you should have seen 5 additional degrees. Of course, this is all dependent on how your main spark table looks. Some tuners tone down the main table and add more into the FF tab.

If you only plan on adding 2 degrees for ethanol on a boosted application, you just wasted a bunch of money. I would take it back to him and make him tune it like the rest of the world does. Or get a new tuner.

Ted's a good remote tuner, but it takes time, and it aint cheap. but you get what u pay for. Or if you are in Florida, go see Howard at Redline in Pompano beach.

[eLeSthree]

I threw 5.5 degrees into my Flex Fuel table on my CTS-V and it made a HUGE difference.

[Surfdog SS]

Originally Posted by eLeSthree

I threw 5.5 degrees into my Flex Fuel table on my CTS-V and it made a HUGE difference.

Thanks man I'll reach back out to him and maybe set up another tuning day to go through it. Maybe he just ran out of time and didn't want to mess with it. He said typically he sees a 30hp gain with that starting point and since i didnt gain anything he didn't add more. Howard is on my radar to go see for a final tune after I do the aux pump. And we are at 16 degrees on 8# final numbers were right at 600 on a mustang dyno, gained around 70-75 from the cam.

[FasNuf]

I thought I was reading that wrong about the 2* because you mentioned they were very familiar with tuning.
eLeSthree is totally right on the added spark. I might be a little heavy on my spark but max load on the high octane rpm is 19* and I added a max of 7* on the ethanol table. Now mine isn't dyno tuned yet, but my butt dyno can totally feel the difference between pump and E60.

[dreksnot]

This is what's meant by that FF percentage proportional multiplier chart, and then the typical FF timing adder when running FF. The additional timing added to the MBT for FF is what percentage (by the multiplier table) X what spark is in the FF table.

[eLeSthree]

Originally Posted by dreksnot

This is what's meant by that FF percentage proportional multiplier chart, and then the typical FF timing adder when running FF. The additional timing added to the MBT for FF is what percentage (by the multiplier table) X what spark is in the FF table.

Yours could be called a bit "aggressive". But i understand your approach. I do sort of the same with the V's tune. I use %75 at %50.


My camaro's tuner used a linear line in the multi comp table.

[dreksnot]

Originally Posted by eLeSthree

... Yours could be called a bit "aggressive..."

It's with intent. The usual 91 octane is E10 and the local E85 station is E67. Since that's what would be in the tank when I head to the strip, I just wanted to use that percentage as the max timing increase and tune for that. Anything above that percentage is just luxury (safety) insurance.